In general, an electronic apparatus is provided with a receptacle so as to transmit and receive data between electronic apparatus through a detachable cable.
In the receptacle which is provided for an electronic apparatus and the cable, a directional plug is formed in the cable so as not to deviate terminal pin arrangements from each other at the time of mutual connection, and thus the cable can be connected to the receptacle in only a specific direction.
When a plug is directional, a user has to insert the plug into the receptacle after checking the insertion direction, which is inconvenient to the user.
In order to improve defectiveness of the directional plug, Korean Patent Application Laid-open No. 2013-0050269 discloses a structure in which a non-directional plug can be coupled to a receptacle without distinction of up and down.
Recently, various optical/electrical connectors that can transmit both an optical signal and an electrical signal have been developed. PCT International Publication No. WO2008/121731 discloses an optical universal serial bus that can transmit both an electrical signal and an optical signal.
However, the optical universal serial bus has defectiveness that it cannot be connected in an inverted state due to a directional connection structure thereof.
Particularly, in order to transmit light, an optical fiber or an optical waveguide should not be exposed from the surface of a plug and an end thereof has to be formed on a longitudinal end face facing the receptacle. When a portion for transmitting light and a portion for receiving light are separately provided, two optical ports have to be formed on the longitudinal end faces of the plug. In this case, even when the plug has a shape which can be inserted into the receptacle in an inverted state so as to be compatible with each other, there is a problem in that an optical reception port and an optical transmission port may be exchanged and normal transmission of a signal may not be enabled when the plug is mounted in an inverted state or the cable is twisted in the extending direction thereof.